Defensive publication



OM DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at the request of the applicant or owner in accordance with the Notice of Apr. 11, 1968, 849 O.G. 1221. Identification is by serial number of the application and the heading indicates the number of pages of specification, including claims, and of sheets of drawing contained in the application as originally filed. The flle of this application is available to the public for inspection reproduction may be purchased for 30 cents per sheet.

Applications published under the Defensive Publication Program have not been examined as to the merits of alleged invention. The Patent Oflice makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED JULY 29, 1969 815 499 PHOSPHATE BUFFER S IN PHOTOGRAPHIC ELEMENTS Richard F. Bulgin, 37 Hastings Way, Croxley Green, Herts, England Filed Apr. 11, 1969. Published July 29, 1969 Int. Cl. G03c 5/38 US. Cl. 9661 No Drawing. 17 Pages Specification Buifers, i.e., compounds which maintain a desired concentration of hydrogen ion and hydroxide ion or a desired pH level, such as phosphate bulfers in photographic elements containing a developer and/or stabilizer such as o-mercaptobenzoic acid, upon processing the element, provide (a) increased maximum density, (b) less tendency to stain and (c) improved stability. Bulfers in photographic elements are useful, for example, in stabilization processing. 

